Transistor devices are utilized in a wide variety of electronic circuit applications. Field-Effect Transistor (FET) devices typically include a drain lead, a source lead, and a gate lead. A channel is disposed between the drain and source, and the channel is the portion of the FET device that conducts current when the FET device is turned on. The gate is the control input of the device which is utilized to control the current flow in the channel.
In various circuit applications, FET devices may be utilized as two-port active devices. In a two-port configuration, two of the three FET leads serve as the input and output ports, and the third FET lead is utilized as the common connection which is connected to the ground potential of the circuit. Depending upon the particular two-port configuration, any one of the three FET leads can be utilized as either the input port, output port, or common connection.